Mono(2-Ethylhexyl) Phthalate Induces Inflammatory and Angiogenic Alterations Mediated by the PI3K/AKT Pathway in HTR-8/SVneo Trophoblastic Cells.

Abstract

Exposure to mono(2-ethylhexyl) phthalate (MEHP) during pregnancy has been associated with adverse pregnancy and birth outcomes characterized by extravillous trophoblast (EVT) abnormal function. Previous reports have suggested that MEHP can activate the PI3K/AKT pathway in EVT cells, a pathway known to regulate inflammation and angiogenesis in these cells. However, the molecular effects of MEHP on crucial EVT functions such as inflammatory and angiogenic homeostasis remain unexplored. This study aimed to characterize the role of the PI3K/AKT pathway as a mechanism of action of MEHP activity, as well as its effects on inflammatory and angiogenic soluble molecules in HTR-8/Svneo EVT human-derived cells. The results showed that a low (5 μM) MEHP concentration increased AKT phosphorylation, but a high (200 μM) concentration did not. Conversely, a high MEHP concentration, but not a low concentration, promoted nuclear translocation of p65 in a PI3K-dependent manner. Notably, distinct patterns of cytokines were transcriptionally and secretorily activated by high and low concentrations of MEHP. IL1B, CXCL8, and TNF were transcriptionally upregulated by MEHP 5 μM, while gene expression and secretion of IL-6 were induced by MEHP 200 μM, suggesting a biphasic inflammatory dose response. In addition, both MEHP concentrations upregulated the expression of angiogenic molecules (VEGF, PGF, and ANGPTL4) and impaired migration and tube formation in HTR-8/Svneo cells. Both inflammatory and angiogenic responses induced by MEHP were inhibited by the PI3K inhibitor LY294002. Collectively, these data demonstrate that MEHP induces inflammation and impairs angiogenesis partly via PI3K/AKT in HTR-8/SVneo cells. These findings may help to understand previous clinical associations between MEHP exposure and placental pathophysiology.